一个实现分页浏览的程序

小弟(是个新手)写了一个关于分页浏览的程序,可是当浏览到第2页时再怎么点"下一页"它都只停留在第2页,而不管在第几页,再点"上一页时"它就只回到第1页,搞了几天了,就是找不出问题在哪里,请教各位大哥,看我的问题出在哪里?如果你们有更好的实现方法还请赐教!谢谢!

后台代码如下:



using System;

using System.Collections;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Web;

using System.Web.SessionState;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.HtmlControls;

namespace ArticleCenter

{

/// <summary>

/// DisplayArticlesByCategory 的摘要说明。

/// </summary>

public class DisplayArticlesByCategory : System.Web.UI.Page

{

protected System.Web.UI.WebControls.Button btnFirst;

protected System.Web.UI.WebControls.Button btnPrevious;

protected System.Web.UI.WebControls.Button btnLast;

protected System.Web.UI.WebControls.DropDownList ddPage;

protected System.Web.UI.WebControls.Label lblCurrentPage;

protected System.Web.UI.WebControls.Label lblTotalPages;

protected System.Web.UI.WebControls.Table tableArticles;

protected System.Web.UI.WebControls.Button btnNext;

ArrayList arts=new ArrayList();

private static readonly int PAGE_SIZE=3;

public int CurrentPage

{

get{return int.Parse(lblCurrentPage.Text);}

set{lblCurrentPage.Text=Convert.ToString(value);}

}

public int TotalPages

{

get{return int.Parse(lblTotalPages.Text);}

set

{

lblTotalPages.Text=Convert.ToString(value);

//因为最大页数发生改变，所以要重新设置

//下拉列表ddPages的内容

ddPage.Items.Clear();

if(value>0)

{

ddPage.Items.Add(" ");

for(int i=1;i<=value;i++)

ddPage.Items.Add(i.ToString());

}

}

}

//设置导航按钮的状态

private void EnableDisableButtons(int iTotalPages)

{

btnFirst.Enabled=(CurrentPage<=1)?false:true;

btnPrevious.Enabled=(CurrentPage<=1)?false:true;

btnNext.Enabled=(CurrentPage<iTotalPages)?true:false;

btnLast.Enabled=(CurrentPage<iTotalPages)?true:false;

}



private void Page_Load(object sender, System.EventArgs e)

{

// 在此处放置用户代码以初始化页面



CurrentPage=1;

if(Request.QueryString["catid"]==null) return;

arts=Yoursun.Business.ArtCategory.GetArticles(Convert.ToInt32(Request.QueryString["catid"]),-1);

int totalCount=arts.Count;

if((totalCount%PAGE_SIZE)==0) TotalPages=totalCount/PAGE_SIZE;

else TotalPages=(totalCount/PAGE_SIZE)+1;

if(TotalPages==0) CurrentPage=0;

DispArticle(arts);

EnableDisableButtons(TotalPages);

}

#region Web 窗体设计器生成的代码

override protected void OnInit(EventArgs e)

{

//

// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。

//

InitializeComponent();

base.OnInit(e);

}



/// <summary>

/// 设计器支持所需的方法 - 不要使用代码编辑器修改

/// 此方法的内容。

/// </summary>

private void InitializeComponent()

{

this.btnFirst.Click += new System.EventHandler(this.btnFirst_Click);

this.btnPrevious.Click += new System.EventHandler(this.btnPrevious_Click);

this.btnLast.Click += new System.EventHandler(this.btnLast_Click);

this.btnNext.Click += new System.EventHandler(this.btnNext_Click);

this.ddPage.SelectedIndexChanged += new System.EventHandler(this.ddPage_SelectedIndexChanged);

this.Load += new System.EventHandler(this.Page_Load);

}

#endregion

private void DispArticle(ArrayList arts)

{

//添加表格头部

tableArticles.Rows.Clear();



TableRow headRow=new TableRow();



TableCell headCellImg=new TableCell();

headCellImg.Text="<img src\"images/smile.gif\">";

headCellImg.Width=20;

headRow.Cells.Add(headCellImg);

TableCell headCellTitle=new TableCell();

headCellTitle.Text="标题";

headCellTitle.Width=120;

headRow.Cells.Add(headCellTitle);

TableCell headCellDate=new TableCell();

headCellDate.Text="日期";

headCellDate.Width=120;

headRow.Cells.Add(headCellDate);

tableArticles.Rows.Add(headRow);

//形成表格内容

int startIndex=(CurrentPage-1)*PAGE_SIZE;

int endIndex=(startIndex+PAGE_SIZE>arts.Count)?arts.Count:(startIndex+PAGE_SIZE);

for(int i=startIndex;i<endIndex;i++)

{

Yoursun.Data.ArticleDetails art=(Yoursun.Data.ArticleDetails)arts[i];

TableCell cellImg=new TableCell();

cellImg.Text="<img src=\"images/文章.gif\">";

cellImg.Width=20;

TableCell cellTitle=new TableCell();

HyperLink link=new HyperLink();

link.NavigateUrl="DisplayArticle.aspx?id="+art.ID.ToString();

link.Text=art.Title;

link.Target="content";

link.CssClass="five";

cellTitle.Controls.Add(link);

TableCell cellDate=new TableCell();

cellDate.Text=art.Time.ToLongDateString();

cellDate.Width=120;

cellDate.CssClass="five";

TableRow row=new TableRow();

row.Cells.Add(cellImg);

row.Cells.Add(cellTitle);

row.Cells.Add(cellDate);

tableArticles.Rows.Add(row);

}

}

private void btnFirst_Click(object sender, System.EventArgs e)

{

if(CurrentPage>1)

{

CurrentPage=1;

DispArticle(arts);

EnableDisableButtons(TotalPages);

}

}

private void btnPrevious_Click(object sender, System.EventArgs e)

{

if(CurrentPage>1)

{

CurrentPage--;

DispArticle(arts);

EnableDisableButtons(TotalPages);

}

}

private void btnNext_Click(object sender, System.EventArgs e)

{

if(CurrentPage<TotalPages)

{

CurrentPage++;

DispArticle(arts);

EnableDisableButtons(TotalPages);

}

}

private void btnLast_Click(object sender, System.EventArgs e)

{

if(CurrentPage<TotalPages)

{

CurrentPage=TotalPages;

DispArticle(arts);

EnableDisableButtons(TotalPages);

}

}

private void ddPage_SelectedIndexChanged(object sender, System.EventArgs e)

{



}

}

}